Thanks for the comments, both of you. I'd like to do videos and sound samples, but at my present level of activity, it might take some time. I plan to make a new pickup with copper primary loop... I think the next post will be on that.

No wonder you missed the post. With my posting frequency (which has lately dropped to once a year), I'm surprised and happy that people still read and comment.

I've thought a lot about adding a piece of mahogany to the back of the neck. It would make the neck more familiar to play. But on the other hand, Rick Toone is making very thin one-piece aluminium necks, and some players seem to like it a lot. I haven't played the guitar enough, since I've had a problem fastening the high e string, and I would like to have a more qualified opinion on thin aluminium necks before adding wood to it.

I expect a piece of mahogany on the back of the neck to look well with the rest of the design. But then again, one of the ideas of the guitar is to have the two pieces of aluminium in the neck to act as a truss rod, and I believe that making the back piece much stiffer by adding wood along its length would destroy that particular function.

Congratulations on some excellent design work. I have been workingon transformer-based pickups myself, and I've run into various problems related to supply (finding laminates of the right size, deciding on the correct number of turns, etc.). I have built several pickups of this nature, but I was surprised to see what you had accomplished with your design. Could you post some more info on the design of the pickups in this guitar? (If you are interested, you can hear a demo of my headless 12-string bass by searching on Youtube for "12 string bass demo 1."

Thanks. I am making another transformer pickup with a copper body, again using a sewing machine bobbin for the secondary coil (like the neck pickup here). I plan to do a post on this pickup and my transformer pickups in general; how they work and how they sound. But designing and making them is like alchemy. I can't count the number of turns on the secondary coil, and the characteristics of the primary (one turn) coil are more due to aesthetics and what pieces of metal I've got. The same goes for the iron wire that acts as a transformer core. And for the magnets, which are small neodymiym ones mounted in blind screws.

It would be nice to approach the subject more scientifically. To calculate all the parameters and afterwards comprare the sound of different variations - listening to recordings and analysing the frequency spectrum. But for now, it's too big a task, so I stick to my random approach.

I watched the youtube video. That's an impressive bass, design and sound wise. I can't figure out how it's tuned, though... do the screws between the bridge and the tail piece act as fine tuners?

Thank you for the compliments. The bass is tuned at the end, like your guitar. I use an allen wrench to turn the hex head screws (space is obviously at a premium with 12 direct-drive tuners!) There are more photos at www.12stringbass.net, but I could send more if you want to see them. I recessed the heads into the brass tailpiece for aesthetic reasons. . . I liked the sound a lot also, though due to the number of strings it is a bit heavy in the midrange. The best part is that there isn't any need for large holes in the strings' vibration path, but I am trying to find ways ti increase the output--those pickups are just a bit above "active" bass pickups in terms of voltage. As for the turns, I use a drill press in low-speed mode to make the coils, so i can fairly accurately predict the number of turns. It seems that the couplings are extremely important, and I have had better results with E-I-style transformers than with single-loop types.

So you said you were using iron wire as a transformer core? Could you post a photo of this? I always have bought mini transformers and disassembled them in order to get the laminates (that's the most irritating part--getting laminates is nearly impossible any other way). The neo magnets come from the Japanese equivalent of a dollar store, where I can get ten in one package. The primary is aluminum, since I have read it has nearly the same resistance as copper, but is easier to buy and cut.

You can see the wire on the neck pickup in the pictures above. It's green florist's wire. It's the same as in old fashioned hedgehog transformers (see e.g. http://telephonecollecting.org/hedgehog.html). I'll use black wire on the next pickup, I'm making -it'll look better. That pickup has a brass body, btw. Aluminium would have been better, resistance wise, but I wanted the contrast to the alu body.

It's an ingenious tuner you made. A beautiful solution to the problem of tuning so many strings.

Thanks for the compliment again! At the moment I am trying to figure out the right sort of configuration for the transformer pickups. I have tried C-style and EI-style cores, and the EI-types seem to have better coupling (judged by higher output). So far, I have had next to no luck at all with cores that don't interleave, and so I am a bit limited in what I can do since parts are rather hard to come by. I will try the hedgehog-style wire core as soon as possible and get back to you. Have you heard of Erno Zwaan? He wrote a great guitarmaking book called "Animal Magnetism for Musicians." I got some very nice ideas from there.

Hello! Maybe I'm totally blind but don't understand how the tuners work... how are they tightening the strings? I can't see where the strings balls go :-pIs there a picture that explains it?Anyway, the guitar looks awesome!